Ink jet printers employ ink jet pens for generating an image on printer media. Pens normally include a housing defining a chamber filled with liquid ink, and a print head attached to the housing in communication with the chamber. The print head has a multitude of independently addressable orifices for expelling small droplets of ink onto the media. If one of the orifices should become clogged by a particle from within the chamber, the pen is considered to have failed. Such failures may be analyzed to determine the source of the contaminant particle, providing an opportunity to address a possible source of contamination introduced during pen manufacturing. Conventional failure analysis techniques have required aggressive measures to dismantle failed ink jet pens. A passage for draining ink must be formed, typically by cutting away a housing seal with a knife. Then, the ball cork must be pressed into the pen. A vent hole is created in the pen housing with a soldering iron to relieve the vacuum that would be generated as ink drains. The vent hole size is critical, as it must be large enough to admit sufficient air, yet not so large as to damage the ink-containing reservoir inside the housing. Such a process requires repeated cleaning and purging of a drain tube and a vent tube to reduce unwanted ink spillage. Also, the use of sharp or heated tools presents safety risks to personnel.
These disadvantages are overcome or reduced by providing a service apparatus for servicing an ink jet pen having a housing defining an ink reservoir and including a print head connected to the housing in communication with the reservoir. The apparatus includes an elongated probe having first and second passages, a fluid supply conduit in communication with the first passage, a drain conduit in communication with the second passage, a fluid receptacle separate from the probe, and a vacuum source in communication with the receptacle. The apparatus may be operated by connecting a pen to the fluid conduit to provide fluid communication between the conduit and the reservoir, draining ink from the reservoir through the fluid conduit, generating a flow of rinse fluid into the reservoir, draining the rinse fluid from the reservoir; and expelling ink through the print head.